Simon Hughes elbowed his way back into contention for the vacant leadership of the Liberal Democrat party yesterday with an uninhibited display of his radical credentials. They included higher tax rates for the rich, civil liberties for all, and a promise never to enter a coalition government without a commitment to proportional representation (PR) voting at Westminster - the Lib Dem holy grail.

Twenty-four hours after being forced by the Sun newspaper to admit to a bisexual past, the MP for North Southwark and Bermondsey went to Manchester as planned to make his formal campaign launch exactly five weeks before ballot papers cast by up to 70,000 members are due to be counted.

In Oxford yesterday, the third man in the contest, Chris Huhne, declared his belief in local decision making in public services such as the NHS even as he called for more international cooperation on global issues such as pollution. "I want to use the tax system to attack 'sins' such as pollution and take the poor out of income tax completely," he said.

Sir Menzies ("Ming") Campbell managed a different kind of boost, a £3,750 bet at 8/15 by a high-rolling telephone punter in Berkshire which prompted Ladbrokes to shorten his odds to 1/2 after he drifted out to 8/13 following sustained support for second favourite Mr Huhne, now at 9/4. Mr Hughes dipped from 5/1 to 6/1.

Mr Hughes noted that David Lloyd George and Winston Churchill, two giants of the last Liberal election landslide - in 1906 - had strong Mancunian connections and that their "private predelictions" might not have withstood "the sort of 2006 news coverage that it's been my lot to face over the last 48 hours". But Mr Hughes reinforced his plea on personal weaknesses with a reminder of why he is the activists' favourite son.

"We have regularly confounded the doubters and achieved under Charles Kennedy our best election results in generations.

"It is time to aim for even greater success in 2010. This is a time for us to be confident and outward looking. We should not simply be thinking about holding on to what we have gained. We should be looking to take new territory."

Pledging his own "commitment and ambition" in 25 years of frontline politics, Mr Hughes declared: "Everyone knows that under my leadership there would be no question of entering a coalition for the sake of a ministerial position. Everyone knows that the first precondition of any partnership would be a properly representative parliament."

All three candidates stress social justice, good public services and "fair taxation" - though Mr Kennedy had been edging away from a 50% tax rate on incomes above £100,000, fearful it might hurt in marginal southern seats.

"But true freedom means a just and fair society. A country where the poorest pay more of their income in tax than the rich can never be seen as fair. We were absolutely right at the last election to propose a higher rate of tax for those most able to pay, to fund our priority programmes and to cut the tax burden for those on low incomes. I remain absolutely committed to this principle," Mr Hughes said.

From the blogs

I know at least half a dozen friends who live in Bermondsey and identify as bisexual, so he does represent his constituentsSean, Pinknews.co.uk

Simon Hughes is bisexual. You'd expect me, being highly prejudiced in favour of homosexuality, to be cheering for him. I hate his guts. I hated him before he came out, and I hate him more nowJae, faultytowershotel.blogspot.com

Been there, done that. Had boyfriends. Had girlfriends. Got married, tried for kids. Got divorced, moved to the boonies. Big fat hairy deal. It's the freaking LIBERAL party, this should SO not be a big deal. But that's the British media for you, they love some gossip to cluck overAndy, smirkingchimp.com